binutils-gdb/binutils/dwarf.h
Nick Clifton dda8d76d0d Add support to readelf and objdump for following links to separate debug information files.
Hi Guys,

  I am applying the rather large patch attached to this email to enhance
  the readelf and objdump programs so that they now have the ability to
  follow links to separate debug info files.  (As requested by PR
  15152).  So for example whereas before we had this output:

    $ readelf -wi main.exe

    Contents of the .debug_info section:
    [...]
    <15>   DW_AT_comp_dir    : (alt indirect string, offset: 0x30c)
    [...]

  With the new option enabled we get:

    $ readelf -wiK main.exe

    main.exe: Found separate debug info file: dwz.debug
    Contents of the .debug_info section (loaded from main.exe):
    [...]
    <15>   DW_AT_comp_dir    : (alt indirect string, offset: 0x30c) /home/nickc/Downloads/dwzm
    [...]

  The link following feature also means that we can get two lots of
  output if the same section exists in both the main file and the
  separate debug info file:

    $ readelf -wiK main.exe
    main.exe: Found separate debug info file: dwz.debug
    Contents of the .debug_info section (loaded from main.exe):
    [...]
    Contents of the .debug_info section (loaded from dwz.debug):
    [...]

  The patch also adds the ability to display the contents of debuglink
  sections:

    $ readelf -wk main.exe
    Contents of the .gnu_debugaltlink section:

      Separate debug info file: dwz.debug
      Build-ID (0x14 bytes):
     c4 a8 89 8d 64 cf 70 8a 35 68 21 f2 ed 24 45 3e 18 7a 7a 93

  Naturally there are long versions of these options (=follow-links and
  =links).  The documentation has been updated as well, and since both
  readelf and objdump use the same set of debug display options, I have
  moved the text into a separate file.  There are also a couple of new
  binutils tests to exercise the new behaviour.

  There are a couple of missing features in the current patch however,
  although I do intend to address them in follow up submissions:

  Firstly the code does not check the build-id inside separate debug
  info files when it is searching for a file specified by a
  .gnu_debugaltlink section.  It just assumes that if the file is there,
  then it contains the information being sought.

  Secondly I have not checked the DWARF-5 version of these link
  features, so there will probably be code to add there.

  Thirdly I have only implemented link following for the
  DW_FORM_GNU_strp_alt format.  Other alternate formats (eg
  DW_FORM_GNU_ref_alt) have yet to be implemented.

  Lastly, whilst implementing this feature I found it necessary to move
  some of the global variables used by readelf (eg section_headers) into
  a structure that can be passed around.  I have moved all of the global
  variables that were necessary to get the patch working, but I need to
  complete the operation and move the remaining, file-specific variables
  (eg dynamic_strings).

Cheers
  Nick

binutils	PR 15152
	* dwarf.h (enum dwarf_section_display_enum): Add gnu_debuglink,
	gnu_debugaltlink and separate_debug_str.
	(struct dwarf_section): Add filename field.
	Add prototypes for load_separate_debug_file, close_debug_file and
	open_debug_file.
	* dwarf.c (do_debug_links): New.
	(do_follow_links): New.
	(separate_debug_file, separate_debug_filename): New.
	(fetch_alt_indirect_string): New function.  Retrieves a string
	from the debug string table in the separate debug info file.
	(read_and_display_attr_value): Use it with DW_FORM_GNU_strp_alt.
	(load_debug_section_with_follow): New function.  Like
	load_debug_section, but if the first attempt fails, then tries
	again in the separate debug info file.
	(introduce): New function.
	(process_debug_info): Use load_debug_section_with_follow and
	introduce.
	(load_debug_info): Likewise.
	(display_debug_lines_raw): Likewise.
	(display_debug_lines_decoded): Likewise.
	(display_debug_macinfo): Likewise.
	(display_debug_macro): Likewise.
	(display_debug_abbrev): Likewise.
	(display_debug_loc): Likewise.
	(display_debug_str): Likewise.
	(display_debug_aranges): Likewise.
	(display_debug_addr); Likewise.
	(display_debug_frames): Likewise.
	(display_gdb_index): Likewise.
	(process_cu_tu_index): Likewise.
	(load_cu_tu_indexes): Likewise.
	(display_debug_links): New function.  Displays the contents of a
	.gnu_debuglink or .gnu_debugaltlink section.
	(calc_gnu_debuglink_ctc32):New function.  Calculates a CRC32
	value.
	(check_gnu_debuglink): New function.  Checks the CRC of a
	potential separate debug info file.
	(parse_gnu_debuglink): New function.  Reads a CRC value out of a
	.gnu_debuglink section.
	(check_gnu_debugaltlink): New function.
	(parse_gnu_debugaltlink): New function.  Reads the build-id value
	out of a .gnu_debugaltlink section.
	(load_separate_debug_info): New function.  Finds and loads a
	separate debug info file.
	(load_separate_debug_file): New function. Attempts to find and
	follow a link to a separate debug info file.
	(free_debug_memory): Free the separate debug info file
	information.
	(opts_table): Add "follow-links" and "links".
	(dwarf_select_sections_by_letters): Add "k" and "K".
	(debug_displays): Reformat.  Add .gnu-debuglink and
	.gnu_debugaltlink.
	Add an extra entry for .debug_str in a separate debug info file.
	* doc/binutils.texi: Move description of debug dump features
	common to both readelf and objdump into...
	* objdump.c (usage): Add -Wk and -WK.
	(load_specific_debug_section): Initialise the filename field in
	the dwarf_section structure.
	(close_debug_file): New function.
	(open_debug_file): New function.
	(dump_dwarf): Load and dump the separate debug info sections.
	* readelf.c (struct filedata): New structure.  Contains various
	variables that used to be global:
	(current_file_size, string_table, string_table_length, elf_header)
	(section_headers, program_headers, dump_sects, num_dump_sects):
	Move into filedata structure.
	(cmdline): New global variable.  Contains list of sections to dump
	by number, as specified on the command line.
	Add filedata parameter to most functions.
	(load_debug_section): Load the string table if it has not already
	been retrieved.
	(close_file): New function.
	(close_debug_file): New function.
	(open_file): New function.
	(open_debug_file): New function.
	(process_object): Process sections in any separate debug info files.
	* doc/debug.options.texi: New file.  Add description of =links and
	=follow-links options.
	* NEWS: Mention the new feature.
	* elfcomm.c: Have the byte gte functions take a const pointer.
	* elfcomm.h: Update prototypes.
	* testsuite/binutils-all/dw5.W: Update expected output.
	* testsuite/binutils-all/objdump.WL: Update expected output.
	* testsuite/binutils-all/objdump.exp: Add test of -WK and -Wk.
	* testsuite/binutils-all/readelf.exp: Add test of -wK and -wk.
	* testsuite/binutils-all/readelf.k: New file.
	* testsuite/binutils-all/objdump.Wk: New file.
	* testsuite/binutils-all/objdump.WK2: New file.
	* testsuite/binutils-all/linkdebug.s: New file.
	* testsuite/binutils-all/debuglink.s: New file.

gas	* testsuite/gas/avr/large-debug-line-table.d: Update expected
	output.
	* testsuite/gas/elf/dwarf2-11.d: Likewise.
	* testsuite/gas/elf/dwarf2-12.d: Likewise.
	* testsuite/gas/elf/dwarf2-13.d: Likewise.
	* testsuite/gas/elf/dwarf2-14.d: Likewise.
	* testsuite/gas/elf/dwarf2-15.d: Likewise.
	* testsuite/gas/elf/dwarf2-16.d: Likewise.
	* testsuite/gas/elf/dwarf2-17.d: Likewise.
	* testsuite/gas/elf/dwarf2-18.d: Likewise.
	* testsuite/gas/elf/dwarf2-5.d: Likewise.
	* testsuite/gas/elf/dwarf2-6.d: Likewise.
	* testsuite/gas/elf/dwarf2-7.d: Likewise.

ld	* testsuite/ld-avr/gc-section-debugline.d: Update expected
	output.
2017-11-15 11:34:03 +00:00

250 lines
7.2 KiB
C

/* dwarf.h - DWARF support header file
Copyright (C) 2005-2017 Free Software Foundation, Inc.
This file is part of GNU Binutils.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
MA 02110-1301, USA. */
#include "dwarf2.h" /* for enum dwarf_unit_type */
typedef unsigned HOST_WIDEST_INT dwarf_vma;
typedef HOST_WIDEST_INT dwarf_signed_vma;
typedef unsigned HOST_WIDEST_INT dwarf_size_type;
/* Structure found in the .debug_line section. */
typedef struct
{
dwarf_vma li_length;
unsigned short li_version;
dwarf_vma li_prologue_length;
unsigned char li_min_insn_length;
unsigned char li_max_ops_per_insn;
unsigned char li_default_is_stmt;
int li_line_base;
unsigned char li_line_range;
unsigned char li_opcode_base;
unsigned int li_offset_size;
}
DWARF2_Internal_LineInfo;
/* Structure found in .debug_pubnames section. */
typedef struct
{
dwarf_vma pn_length;
unsigned short pn_version;
dwarf_vma pn_offset;
dwarf_vma pn_size;
}
DWARF2_Internal_PubNames;
/* Structure found in .debug_info section. */
typedef struct
{
dwarf_vma cu_length;
unsigned short cu_version;
dwarf_vma cu_abbrev_offset;
unsigned char cu_pointer_size;
enum dwarf_unit_type cu_unit_type;
}
DWARF2_Internal_CompUnit;
/* Structure found in .debug_aranges section. */
typedef struct
{
dwarf_vma ar_length;
unsigned short ar_version;
dwarf_vma ar_info_offset;
unsigned char ar_pointer_size;
unsigned char ar_segment_size;
}
DWARF2_Internal_ARange;
/* N.B. The order here must match the order in debug_displays. */
enum dwarf_section_display_enum
{
abbrev = 0,
aranges,
frame,
info,
line,
pubnames,
gnu_pubnames,
eh_frame,
macinfo,
macro,
str,
line_str,
loc,
loclists,
pubtypes,
gnu_pubtypes,
ranges,
rnglists,
static_func,
static_vars,
types,
weaknames,
gdb_index,
debug_names,
trace_info,
trace_abbrev,
trace_aranges,
info_dwo,
abbrev_dwo,
types_dwo,
line_dwo,
loc_dwo,
macro_dwo,
macinfo_dwo,
str_dwo,
str_index,
str_index_dwo,
debug_addr,
dwp_cu_index,
dwp_tu_index,
gnu_debuglink,
gnu_debugaltlink,
separate_debug_str,
max
};
struct dwarf_section
{
/* A debug section has a different name when it's stored compressed
or not. COMPRESSED_NAME and UNCOMPRESSED_NAME are the two
possibilities. NAME is set to whichever one is used for this
input file, as determined by load_debug_section(). */
const char * uncompressed_name;
const char * compressed_name;
const char * name;
/* If non-NULL then FILENAME is the name of the separate debug info
file containing the section. */
const char * filename;
unsigned char * start;
dwarf_vma address;
dwarf_size_type size;
enum dwarf_section_display_enum abbrev_sec;
/* Used by clients to help them implement the reloc_at callback. */
void * reloc_info;
unsigned long num_relocs;
/* A spare field for random use. */
void * user_data;
};
/* A structure containing the name of a debug section
and a pointer to a function that can decode it. */
struct dwarf_section_display
{
struct dwarf_section section;
int (* display) (struct dwarf_section *, void *);
int * enabled;
bfd_boolean relocate;
};
extern struct dwarf_section_display debug_displays [];
/* This structure records the information that
we extract from the.debug_info section. */
typedef struct
{
unsigned int pointer_size;
unsigned int offset_size;
int dwarf_version;
dwarf_vma cu_offset;
dwarf_vma base_address;
/* This field is filled in when reading the attribute DW_AT_GNU_addr_base and
is used with the form DW_AT_GNU_FORM_addr_index. */
dwarf_vma addr_base;
/* This field is filled in when reading the attribute DW_AT_GNU_ranges_base and
is used when calculating ranges. */
dwarf_vma ranges_base;
/* This is an array of offsets to the location list table. */
dwarf_vma * loc_offsets;
/* This is an array of offsets to the location view table. */
dwarf_vma * loc_views;
int * have_frame_base;
unsigned int num_loc_offsets;
unsigned int max_loc_offsets;
unsigned int num_loc_views;
/* List of .debug_ranges offsets seen in this .debug_info. */
dwarf_vma * range_lists;
unsigned int num_range_lists;
unsigned int max_range_lists;
}
debug_info;
extern unsigned int eh_addr_size;
extern int do_debug_info;
extern int do_debug_abbrevs;
extern int do_debug_lines;
extern int do_debug_pubnames;
extern int do_debug_pubtypes;
extern int do_debug_aranges;
extern int do_debug_ranges;
extern int do_debug_frames;
extern int do_debug_frames_interp;
extern int do_debug_macinfo;
extern int do_debug_str;
extern int do_debug_loc;
extern int do_gdb_index;
extern int do_trace_info;
extern int do_trace_abbrevs;
extern int do_trace_aranges;
extern int do_debug_addr;
extern int do_debug_cu_index;
extern int do_wide;
extern int do_debug_links;
extern int dwarf_cutoff_level;
extern unsigned long dwarf_start_die;
extern int dwarf_check;
extern void init_dwarf_regnames (unsigned int);
extern void init_dwarf_regnames_i386 (void);
extern void init_dwarf_regnames_iamcu (void);
extern void init_dwarf_regnames_x86_64 (void);
extern void init_dwarf_regnames_aarch64 (void);
extern void init_dwarf_regnames_s390 (void);
extern bfd_boolean load_debug_section (enum dwarf_section_display_enum, void *);
extern void free_debug_section (enum dwarf_section_display_enum);
extern void * load_separate_debug_file (void *, const char *);
extern void close_debug_file (void *);
extern void * open_debug_file (const char *);
extern void free_debug_memory (void);
extern void dwarf_select_sections_by_names (const char *);
extern void dwarf_select_sections_by_letters (const char *);
extern void dwarf_select_sections_all (void);
extern unsigned int * find_cu_tu_set (void *, unsigned int);
extern void * cmalloc (size_t, size_t);
extern void * xcalloc2 (size_t, size_t);
extern void * xcmalloc (size_t, size_t);
extern void * xcrealloc (void *, size_t, size_t);
extern dwarf_vma read_leb128 (unsigned char *, unsigned int *, bfd_boolean, const unsigned char * const);
/* A callback into the client. Returns TRUE if there is a
relocation against the given debug section at the given
offset. */
extern bfd_boolean reloc_at (struct dwarf_section *, dwarf_vma);